Download B2-Keywords and definitions

B2 TOPIC 1
Keyword
THE COMPONENTS OF LIFE
Definition
Cells
The basic units of life in which many chemical reactions needed
to sustain life take place.
Relatively rigid structure that surrounds plant and bacterial cells
which supports the cell and helps keep its shape.
Thin layer which forms a semi-permeable barrier around the
cytoplasm of the cell and controls movement of substances into
and out of the cell.
The liquid gel which makes up most of the cell and is where
many chemical reactions take place.
Tiny structures within the cell that carry out specific jobs e.g.
mitochondria.
Contains DNA for making new cells and controls the reactions in
the cell.
The chemical that makes up genes and chromosomes; the
instructions for a cell’s growth and activities.
The site of cellular respiration where glucose is broken down
using oxygen and energy is released so that reactions can happen
in the cell.
Small structure in the cytoplasm of a cell where proteins are
made.
Cell walls are made up of tough cellulose which gives the cell
support and its shape.
Cell wall
Cell membrane
Cytoplasm
Organelles
Nucleus
DNA
Mitochondria
Ribosome
Cellulose
Vacuole
Chloroplast
Chlorophyll
Light microscope
Electron microscope
Chromosomal DNA
Plasmid DNA
Flagella
Chromosomes
Gene
Bases
Double helix
Complementary base pairs
Hydrogen bonds
Genome
Membrane-bound space in the cytoplasm of a plant cell filled with
cell sap; helps support the plant by keeping the cells rigid.
Organelle in plant cells that contains chlorophyll and is where
photosynthesis takes place.
Green substance found in chloroplasts that absorbs energy from
sunlight.
Instrument which magnifies a specimen using light and lenses.
Instrument which magnifies specimens using a beam of electrons.
The DNA which makes up most of the chromosomes of a cell.
A circle of extra DNA found only in bacterial cells.
Whip-like structure found on the outside of some bacterial cells
and other cells which can be moved for movement.
Thread-like structures found in the nucleus of a cell which carries
genetic information.
A section of DNA that codes for a specific protein.
The chemicals that link together at regular intervals the two
strands of a molecule of DNA. They are called adenine, thymine,
guanine and cytosine.
The spiral structure of a DNA molecule produced by two strands
held together by complimentary base pairs.
The bases always pair up in the same way because of the
matching shapes of the molecules. A to T and G to C.
Weak bonds that hold together the base pairs in DNA.
All the genetic information (DNA) of an organism as a list of the
Human genome project
Genetic engineering
Genetically modified
organisms
Golden rice
Beta-carotene
Herbicide
Biodiversity
Mitosis
Meiosis
Diploid
Haploid
Growth
DNA replication
Daughter cells
Parent cell
Asexual reproduction
Sexual reproduction
Gametes
Fertilisation
Zygote
Embryo
Alleles
Clones
Enucleated
Implanted
Uterus
Surrogate mother
Stem cell
order of all the base pairs.
A project to sequence all of the base pairs of the human genome
carried out by many scientists from many different countries
working together.
The process of removing a gene from one organism and inserting
it into the DNA in a cell from another organism.
An organism that has had its genome changed by inserting a
gene from another organism.
Genetically engineered rice which produces beta-carotene in the
rice grains turning them into a golden colour.
Substance in the human diet from which the body makes
Vitamin A.
Chemical which kills plants, usually used on weeds.
The variety of species living within a given area.
Division of a parent cell that produces two genetically identical
diploid cells.
Division of a parent cell that produces two genetically different
haploid cells.
A cell that has two sets of chromosomes. In humans almost all
cells except egg and sperm are diploid.
Having one set of chromosomes as in gametes.
Increase in size, length and mass as well as increase in cell
number.
When the chromosomes are copied before cell division occurs
Cell produced by division of a parent cell.
The cell that divides to produce daughter cells.
The formation of a new individual without fertilisation using the
process of mitosis to create offspring identical to its parent.
The formation of a new individual from the fertilisation of a
female by a male gamete; the individual is genetically different
from its parents.
Sex cell produced in males and females by meiosis.
When two gametes fuse.
A fertilised egg cell.
The ball of cells produced by cell division of the zygote. Early
stage of development of a new individual.
Every gene has an alternative form e.g. eye colour may have a
blue type or brown type eye colour.
An individual created by a form of asexual reproduction to
produce offspring that is genetically identical to the parent.
A cell that has had its nucleus removed.
In reproduction, placing an embryo into the uterus of a female
animal to allow development.
Womb where embryo is implanted for development.
A female who is not related to the embryo that is implanted in her
uterus to develop.
An unspecialised cell that can divide to produce more stem cells or
Embryonic stem cell
Adult stem cell
Differentiated
Genetic code
Amino acid
Protein synthesis
Transcription
mRNA
Uracil
Base triplet (codon)
tRNA
Polypeptide
Mutation
Enzyme
Catalyst
Digestion
Substrate
Active site
Denature
“Lock and key” hypothesis
different kinds of specialised cells.
A cell from an early stage of division of an embryo that can
differentiate and produce almost any type of specialised cell.
A stem cell found in differentiated tissue that can produce few
kinds of differentiated cells.
Cells that become specialised into a specific cell e.g. nerve cell.
The code produced by a specific sequence of bases in DNA.
A small molecule that is the building block of proteins.
The building up of a protein molecule by joining together amino
acids.
When a strand of mRNA is produced by complimentary base
pairing with one strand on the DNA molecule.
The molecule formed during transcription that carries the code
from the chromosome to the ribosome.
A base only found in RNA which replaces the thymine in DNA.
A group of three base pairs that codes for a specific amino acid.
A small RNA molecule that transfers the correct amino acid to
the ribosome during translation so that the correct protein can
be synthesised.
A chain of amino acids that will form part of a protein.
A change in the base sequence of DNA often as a result of
exposure to radiation.
A protein molecule made by living cells that speeds up the rate
of a reaction.
A substance that speeds up the rate of a reaction without being
used up in the reaction.
The breakdown of large insoluble food molecules into small
soluble molecules.
The substance that is changed by an enzyme in a chemical
reaction.
The site on an enzyme molecule that has a special shape that
holds the substrate molecule during the reaction.
The breakdown or change in shape of enzymes due to excess
heat.
An idea that describes the relationship of a substrate and the
active site of an enzyme to help explain how enzymes work.
B2 TOPIC 2
Keyword
ORGANISMS AND ENERGY
Definition
Respiration
A series of reactions occurring in all living cells in which glucose is
broken down to release energy.
Respiration that needs oxygen.
A simple sugar that is broken down in cells to release energy
during respiration. It is also made during photosynthesis.
Tiny blood vessels with thin walls to allow diffusion of substances
into and out of the blood.
The random movement and spreading of particles. When there is
a concentration gradient there is a net diffusion of particles from
an area of high concentration to an area of low concentration.
A situation when a solute is in a gradually increasing concentration
Aerobic respiration
Glucose
Capillaries
Diffusion
Concentration gradient
Gas exchange
Anaerobic respiration
Stroke volume
Cardiac output
Lactic acid
EPOC
Photosynthesis
Starch
Stomata (plural) Stoma
(singular)
Surface area to volume ratio
Limiting factors
Root hair cells
Osmosis
Partially permeable
membrane
Active transport
Xylem
Phloem
Transpiration
Environment
Biodiversity
Ecosystem
Habitat
Distribution
from one region to another.
A process in the lungs in which oxygen diffuses from the lungs into
the blood and carbon dioxide diffuses out of the blood into the
lungs.
Respiration that does not need oxygen.
The volume of blood the heart can pump out with each beat.
The volume of blood the heart can pump out in one minute,
calculated by multiplying the heart rate by the stroke volume.
The waste product of anaerobic respiration in animal cells.
Excess post-exercise oxygen consumption. Period of time after
exercise in which a greater than usual amount of oxygen is needed
by the body which includes the removal of lactic acid. This used to
be called oxygen debt.
A series of enzyme-catalysed reactions carried out in the green
parts of plants. Carbon dioxide and water combine to form
glucose in the presence of light energy from sunlight.
A carbohydrate made by joining together thousands of glucose
molecules.
Pores on the underside surface of a leaf, which when open,
allows gases to diffuse into and out of a leaf.
The total amount of surface area of an object divided by its
volume.
A single factor that when in short supply can limit the rate of a
process such as photosynthesis.
Cells found near the tips of roots that have thin extensions that
look like hairs and gives the cells a large surface area. Water
enters these cells by osmosis.
The diffusion of water from a region of high concentration of
water molecules to a region of low concentration of water
molecules through a partially permeable membrane.
A thin sheet of material that will allow certain substances like
small molecules to pass through e.g. water but not others that
are too large.
Movement of molecules into a cell using energy made in
respiration. Movement is against a concentration gradient e.g.
plant root cells take in salts from the soil in this way.
Tissue made of dead hollow cells that transports water and
dissolved minerals from the roots to other parts of the plant.
Living tissue that transports sugars around a plant.
The evaporation of water vapour from the surface of a plant.
An organisms surroundings, made up of many different factors
such as air, water, soil and other living organisms.
The variety of species present within a given area.
An area in which all the living organisms and all the non-living
physical features in the area form a stable relationship that needs
input from outside the area to remain stable.
The place where an organism usually lives.
The places in which a certain organism can be found within an
Systematic sampling
area.
The numbers of individuals of a species in a given area.
Looking at a small portion of an area or population.
A method of sampling where the locations are selected randomly.
A sample that has approximately the same characteristics as those
of the whole study area.
A simple device used to collect small invertebrates.
A net use to collect insects from long grass or the canopy of a tree
by sweeping it through the grass or leaves.
A net used to collect aquatic organisms from ponds, rivers and
streams.
A trap used to catch small animals that move on the ground. The
animals are unable to escape.
A square frame of known area which is placed on the ground to
get a sample of the organisms living in a small area.
Looking at a small portion of an area or population.
B2 TOPIC 3
Keyword
COMMON SYSTEMS
Definition
Fossil
The preserved traces or remains of an organism which lived a
very long time ago.
The collection of fossils identified from different periods of time
that can be interpreted to form a hypothesis about the evolution
of life on earth.
The development of new species over time through a process of
natural selection.
Five fingered.
Increase in size, length and mass as well as increase in cell
number.
A numeric value that indicates a certain percentage of
observations e.g. the 2oth percentile of a set of data indicates
that 20% of the data points are the same or lower.
Getting longer.
A group of specialised cells that all carry out the same function.
Population size
Sampling
Random sampling
Representative sample
Pooter
Sweep net
Pond net
Pitfall traps
Quadrat
Fossil record
Evolution
Pentadactyl
Growth
Percentile
Elongation
Tissue
Plasma
Red blood cells
Haemoglobin
White blood cells
Antibodies
Platelets
Organ
Deoxygenated
Oxygenated
The liquid component of blood that carries all the suspended cells
and dissolved substances.
Biconcave discs containing haemoglobin that gives blood its red
colour and carries oxygen around the body to the tissues.
A red pigment containing iron found in red blood cells which
carries the oxygen.
Several different types of cells that form part of the bodies
defence system against disease.
Proteins that bind to the micro-organism that causes diseases and
destroys them.
Call fragments that are important in the clotting mechanism of the
blood.
A group of different tissues working together to carry out a
particular function.
Without oxygen.
With oxygen.
Septum
Vena cava
Right atrium
Valves
Right ventricle
Pulmonary artery
Left atrium
Left ventricle
Pulmonary vein
Aorta
Blood vessels
Arteries
Veins
Organ systems
Circulatory system
Digestion
Digestive system
Alimentary canal
Bolus
Saliva
Oesophagus
Peristalsis
Stomach
Small intestine
Villi
Pancreas
Large intestine
Faeces
A thin membrane that separates the two sides of the heart.
A major vein leading to the heart.
One of the four chambers of the heart that receives blood from
the vena cava.
Flaps of tissue in the heart that stop the blood from flowing
backwards.
One of the four chambers of the heart that receives blood from
the right atrium and pumps it into the pulmonary artery.
Arteries that carry deoxygenated blood from the right ventricle
to the lungs.
One of the four chambers of the heart that receives blood from
the pulmonary vein.
One of the four chambers of the heart that receives blood from
the left atrium and pumps it into the aorta.
Veins that carry oxygenated blood from the lungs to the left
atrium.
A major artery leading away from the heart and carrying
oxygenated blood.
Tubes that contain the blood as it flows around the body.
Blood vessels that transport blood away from the heart.
Vessels that transport blood back to the heart.
A group of organs working together to carry out a particular
function in the body.
Organ system involving the heart and blood vessels which
oxygenates blood and moves it around the body.
The breakdown of large insoluble food molecules into small
soluble food molecules.
The system of organs that brings about digestion of food in the
body.
The muscular tube that runs from the mouth to the anus including
the oesophagus, stomach, small intestine and large intestine.
A ball-shaped mass of chewed food.
Lubricates food and makes it easier to swallow. Also contains
amylase which begins carbohydrate digestion.
Muscular tube between the mouth and the stomach.
The waves of muscular contractions that move food along the
alimentary canal.
Organ that produces acid and some enzymes for digestion.
Organ where digestion is completed and nutrients are absorbed
into the bloodstream.
Finger-like folds of the lining of the small intestine which greatly
increases the surface area for the absorption and diffusion of
digested food products into the blood.
Organ that makes digestive enzymes and secretes them into the
first part of the small intestine.
Organ that absorbs water from digested material.
Undigested, waste material.
Anus
Liver
Bile
Gall bladder
Carbohydrate
Protein
Fat
Sugars
Carbohydrase
Amylase
Proteases
Amino acids
Pepsin
Lipases
Fatty acids
Glycerol
Emulsify
Probiotics
Functional foods
Lactobacillus
Bifidobacteria
Plant stanol esters
Cholesterol
Prebiotics
Oligosaccharides
Where undigested food is passed out of the body.
Organ that has a range of functions including secretion of bile.
An alkaline substance made by the gall bladder that helps in fat
digestion.
An organ that stores bile that is made in the liver and releases it
into the small intestine via the bile duct.
Compound made up of carbon, hydrogen and oxygen and used for
energy.
A polymer made up of amino acids.
Chemicals that are used to store energy in organisms.
A group of compounds formed from carbon, hydrogen and
oxygen.
Enzyme which catalyses the breakdown of carbohydrates.
An example of a carbohydrase enzyme which breaks down starch
to simple sugars.
Enzymes which digest proteins into amino acids.
Small molecules that are the building blocks of proteins.
An example of a protease enzyme found in the stomach.
Enzymes that digest fats into fatty acids and glycerol.
Part of the structure of a fat or oil.
Part of the structure of a fat or oil.
Turn into an emulsion, a mixture in which particles of one liquid
are suspended in another liquid.
Foods containing live bacteria that produce lactic acid in the gut
and may improve the health of your digestive system.
Foods which are not eaten for nutritional value but which claim
to make you healthier.
Example of probiotic bacteria.
Example of probiotic bacteria.
Oily substances found in plants that appear to lower blood
cholesterol levels in people.
A fat which is made in the liver and carried around the body in
the blood. High levels are associated with increased risk of heart
disease.
Substances that cannot be digested by human digestive systems
but which acts as food for probiotic bacteria in the intestine.
A type of carbohydrate which is a common prebiotic.